Core catcher



y 1935- .1. H. HOWARD 2,000,389

CORE CATCHER Filed May 19, 1933 "g 12 O O O O 2 0 7 4 2 36 1 Y a; 4 20 ,6 H9, 4

hwen/or John hi Howard Afforney Patented May 7, 1935 2,000,389

UNITED STATES PATENT GORE CATCHER John H. Howard, Huntington Park, Califi, as-

signor to Globe Oil Tools Company, Los Nietos, Calif., a corporation of California Application May 19, 1933, Serial No. 671,889

3 Claims. (Cl. 255-72) This invention relates to a device for use in simple, practical and effective means for holding well drilling operations and relates more particuthe slips or gripping members of a core catcher larly to a core catcher for use in a core drill or against inward movement until the core enters core receiving well bit. It is a general object of the core catcher or app the core Catfiherkl the present invention to provide a simple, practi- Another object of the inve is to Provide a 5 cal core catcher that is dependable in operation. core catcher including core gripping members and One type of core catcher that has gone into means for holding the gripping members against al use involves gripping members or slips premature or undesirable contraction or actuathat are actuated inwardly into gripping engagetion that does not interfere with the free passage ment with the core through cooperation with an of the core into the barrel or with the proper or 1 inclined internal shoulder in the core drill. lhe timely operation of the gripping members. active cooperation of the gripping slips with the Another object of the invention is to provide a inclined shoulder of the drill is caused by longimeans for holding the core gripping members of tudinal movement of the core catcher relative to a core catcher extended or unactuated until the the body of the drill. The pitch or inclination of core enters the core catcher, that may be used 15 the slip actuating inclined shoulder on the inwith various forms of core catchers and that does terior of the drill is usually comparatively slight not require the alteration or modification of the so that the slips may be actuated inwardly with core catcher or core drill. suficient force to properly grip the core. In as- Another object of the invention is to provide a semblying or making up the drilling string when simple, inexpensive member or structure adapted 20 a core drill is being run into the well, it is necesto be positioned Within the series of gripping sary to set or suspend the string on the slips in members of a core catcher that has a releasable the rotary table each time a stand of drill pipe or frangible connection with the core catcher,v is added to the string. The jarring action to which connection is released or broken when the which the drilling string is subjected each time core enters the core catcher, allowing the. said 25 the string is set on the rotary table slips, jars or member or structureto be forced upwardly into forces the core catcher downwardly so that its the core barrel so that the core catcher maybe slips or gripping members are forced inwardly actuated in the usual manner when desired. through cooperation with the inclined shoulder on Another object of the invention is to provide a so the interior of the drill. In many instances, this means or device for holding the gripping slips or downward movement of the core catcher causes members of a core catcher against prematurethe slips to move downwardly on the inclined operation, that may be easily .and quickly posishoulder a considerable distance so that the core tioned or mounted in the core catcher. catcher becomes immovably wedged on the in- A further object of the invention is to provide clined shoulder and when the drilling operation is a core catcher including slips operable into gripstarted, the upper end of the core passes upwardly ping engagement with a core upon relative longiinto the caught or wedged core catcher. The uptudinal movement between the core drill and core per end of a core is often rounded or reduced in catcher and a means for holding the core catcher v size and may pass upwardly between the. conagainst longitudinal movement relative to the tracted slips of the core catcher, thus increasing drill, said means being releasable bya core enter- 40 the friction between the slips and the inclined ing the core catcher. shoulder so that the core catcher cannot move Further objects and features ofthe invention upwardly to allow the core to freely enter the core will be best and fully understood from the followbarrel. v ing detailed description of typical forms and-ap-' An object of this invention is to provide a core plications of the invention, throughout which de- 45 catcher that cannot become wedged in the core scription reference ismade to the accompanying drill or made inoperative by the jars or shocks to drawing, in which: 1 v g which it may be subjected when the core drill is Fig. 1 is a side elevation of a typical core drill being run into the well. Y a with the lower portion appearing vertical cross Another object of the invention is to provide a section to illustrate one form of the present in 50 core catcher including slips or gripping members vention arranged in the drill. Fig. 2 isanen-"v operable inwardly to grip a core and means for larged bottom plan or elevation of the core catch-t. holding the gripping members outward or unacer illustrated in Fig. 12 Fig. 3 is a vertical detuated until the core has entered the core catcher. tailed sectional view of another form of the inven-' 1 Another object of the invention is to provide a tion, and Fig. 4 isa top or plan viewof the means 55 embodied in the form of the invention illustrated in Fig. 3 for releasably holding the slips against operation.

In accordance with its broader aspects, the present invention may be embodied in or carried out in connection with core catchers for use in various kinds of core drills and core catchers varying considerably in construction, design, etc. Throughout the following detailed disclosure, I will describe two typical forms or applications of the invention for use in a more or less typical core drill, it being understood that the invention is not to be construed as limited or restricted to the specific details about to be set forth, but is to be taken as including any features or modifications that may fall within the scope of the claims.

The core drill illustrated in Fig. 1 of the drawing includes, an outer barrel l0 provided at its upper end with a sub II for facilitating connection of the drill with the drilling string. A sub I2 is provided on the lower end of the outer barrel l0 and carries a sub or tubular member I3 in which the core catcher operates. An inner barrel II is provided within the barrel ID to receive the core. The lower end portion of the core barrel or inner barrel H is threaded into the member l3 and its lower end forms a downwardly facing shoulder IS. A tubular or annular bit head I6 is provided on the lower end of the member l3 and carries spaced cutting parts or blades I1. The cutting blades II are operableto make an annular cut in the formation and thus form a core which may be received in the core barrel ll. A downwardly and inwardly inclined shoulder I8 is provided on the interior oi the member |3 to actuate the gripping parts of the core catcher. The circulation fluid is passed downwardly between the two barrels IO and I4 and is conducted downwardly through fluid passages l9 and 20 to discharge from the lower end of the bit head l6. As the present invention is not primarily concerned with the specific construction of the core drill the details described above are not to be taken as restricting the scope or application of the invention.

The core catcher illustrated in Figs. 1 and 2 of the drawing includes, generally, a body 2| shiftable longitudinally in the opening 22 of the member i3, gripping members or slips 23 carried by the body 2| and operable inwardly to grip a core through cooperation with the inclined shoulder l6, and means 24 for preventing premature or undesirable operation of the slips.

The body 2| of the core catcher is 'tubular, and is proportioned so that it may freely shift longitudinally in the opening 22 of the member l3. The central longitudinal opening 26 of the body 2| is adapted to .receive or pass the core as it passes upwardly into the barrel Id. The upward movement of the body 2|, relative to the core drill, is limited by the engagement of its upper end with the shoulder I! as illustratedin Fig. 1 of the drawing. The downward movement of the body 2| relative to the drill is usually limited by engagement of the slips 23 with the inclined shoulder l3 as will be subsequently described.

The gripping members or slips 23 are operable inwardly into gripping engagement with a core through cooperation with the inclined shoulder l3 upon downward movement of the body 2| relative to'the body member l3 0! the drill. The slips 23 are attached to or suspended-from the body 2| by flexible members or spring members 26. Any desirable or suitable number of circumfcrentially spaced slips 23 may beembodied in ble members 26 and blocks 21 seated in the grooves. The flexible members 26 project downwardly from the body 2| and the slips 23 are attached to the lower-end portions of the members. The rear or outer sides of the slips 23 are inclined to have effective sliding engagement with the inclined shoulder l8. Grooves or notches 29 are provided in the outer sides of the slips 23 to receive the end portions, of the flexible members 26. Rivets 3| attach the slips to the springs 26.

The inner faces of the slips 23 are serrated or toothed so as to dependably grip the core. The springs or flexible members 26 project upwardly from the body 2| and their projecting-upper portions are bent or bowed inwardly so as to engage the core to resist movement of the core catcher relative to the core and to aid in gripping and supporting the core. During the drilling operation when the core is being received in the drill, the upper end portions 33 of the spring members 26 yieldingly engage the core to resist downward movement of the core catcher so that the body 2| of the core catcher is maintained in its uppermost position where its upper end engages the shoulder l6. When the core catcher is in the position just mentioned, the slips 23 are extended or. unactuated. It will be apparent that when the drill is raised or moved upwardly that the upper portions 33 of the spring members yieldingly engage the core to resist movement of the core catcher so that thegripping members or slips 23 are actuated inwardly against the core by the upwardly moving inclined shoulder |6.

The means 24 for preventing premature or undesirable operation of the gripping slips 23 holds the slips 23 in their fully out or unactuated positions until the core is received in the drill. By holding the gripping slips '23 outwardly in their unactuated position, the. means 24 prevents downward movement of the body 2| of the core catcher. In'the embodiment of the invention illustrated in Figs. 1 and 2 of the drawing, the means 24 includes an element or member 36 adapted to be arranged within the core catcher.

The member 36 is provided to engage the inner sides of the slips 23 to positively prevent inward movement or contraction of the slips. In accordance with the broader principles of the invention, the member 36 may be of any suitable shape and the invention contemplates the construction or formation of the member 36 of any suitable material. The slip controlling member 36 may be made of wood, metal, a frangible material such as a ceramic product, or any other suitable rela- The flexible members 26 extively inexpensive material. In the particular case illustrated in the drawing. the slip controlling member 36 is formed of wood, and is in the nature of a cylinder or tube having a cylindrical exterior, and a central longitudinal opening 36.

The walls of they member 36 are of suitable thickness to have the desired strength. In accordance' with the invention, the slip controlling member 35 is proportioned so that it holds the slips 23 outward against the walls of the opening 22 or against the extreme upper end portion of 'the inclined shoulder II. In the particular proportioning and relationingpf parts illustrated in the drawing, the slips 23 are at the extreme uppere'nd portion of the inclined shoulder l6 when the upper end of the body 2| is in engagement with the shoulder l 5, and the member 35 operates to hold the slips outwardly against the upper portion of the shoulder. As the control member 35 prevents inward movement of the slips 23, the body 2| is held against longitudinal movement relative to the body of the drill and the slips cannot move downwardly on the shoulder l8. The member 35 is rigid and sufliciently strong to dependably resist any tendency of the slips 23 to move downwardly on the shoulder 18 under the influence of the jarring action to which they may be subjected when the drill is run into the well.

The invention includes a releasable or frangible connection between the member 35 and the body 2| of the core catcher that holds the member 35 in its operative position during the running of the drill into the well and until a core is received in the drill. One or more connecting members or pins 38 extend through radial or transverse openings 31 in the body 2! and extend into the member 35. The pins 38 are in the nature of frangible pins or shear pins that are sheared off when the lower end of the member 35 engages a core during the drilling operation. In practice, the pins 38 may be in the nature of common nails passed through the openings 31 in the body 2! and driven into the member 35 or passed into already formed openings in the member. In the particular embodiment of the invention illustrated in the drawing, there are two pins 38 extending through diametrically opposite openings 37 in the body 2i.

It is believed that the operation of the form of the invention illustrated in Figs. 1 and 2 of the drawing will be readily apparent from the foregoing detailed description. The member 35 may be assembled in the core catcher prior to the arrangement or assembling of the core catcher in the drill. The member 35 may be easily and quickly assembled in the core catcher and attached to the body 2| by means of the pins or nails 36. slips 23 and the body 2! in the positions illus- 'trated in Fig. 1 of the drawing when the drill is run into the well, and until a core is received in the drill. As described above, the member 35 is proportioned and related to the other parts .so that it holds the slips 23 outwardly against the upper end portion of the inclined shoulder l8 thereby holding the entire core catcher against longitudinal movement in the drill. In this manner the member 35 prevents the slips 23 from being actuated inwardly through cooperation with the shoulder l8 by any jarring action to which the core catcher may be subjected when the drill is run into the well bore. When drilling is started the cutters I! make an annular cut in the formation leaving a central core which is received in the tubular bit head Hi. When the core is a certain length its upper end may be received in the opening 36 of the member 35 or the lower end of the member 35 may strike the upper end of the core. The upper end of the core may be considerably reduced in size in which case it may be received by the opening 36 of the member 35. As the core drill is fed downwardly during the drilling operaticn, the engagement of the member 35 with the core results in shearing of the pins 36 so that the member 35 is forced upwardly from between the slips 23 and finally entirely out of the core catcher. Upon the member 35 being forced upwardly out of engagement with the The control member 35 holds the" slips 23, the slips are free to be actuated, however, the engagement of the member 35 with the upper portions 33 of the spring members holds the core catcher in the up position where the upper end of its body is in engagement with the shoulder l5. When the member 35 is finally forced out of engagement with the spring parts 33 the core takes its place so that the yielding engagement between the string members 33 and the core maintains the core catcher in its up or unactuated position. When it is desired to remove the drill or break the core loose from the formation, the drill is raised or pulled upwardly and the engagement of the spring parts 33 with the core resists upward movement of the core catcher so that the inclined shoulder l8 moves upwardly relative to the slips 23 and forces the slips inwardly into tight gripping engagement with the core. When the member 35 is forced upwardly through the core catcher by the entering core, it is free to be supported on the upper end of the core and is readily received in the core barrel it so thatit does not in any way interfere with the proper operation of the drill. Further, the slip controlling member 35, in being entirely free within the barrel I4 after leaving the core catcher, does not spoil or break up the core.

The embodiment of the invention illustrated in Figs. 3 and 4 of the drawing includes, generally, a body Zi slips 23 connected with the body, and means 40 for preventing premature operation of the slips.

The body 2i and slips 23 may be identical with the corresponding parts of the form of the invention illustrated in Figs. 1 and 2 of the drawing. The slips 23 are carried by spring members M attached to the tubular body 2i. The spring members M have upper portions 42 for engaging the core to resist movement of the core catcher relative to the core. The inner sides of the slips 23 are serrated or provided with teeth 54 for gripping the core. The outer sides of the gripping members or slips 23 are inclined to slidably cooperate with the shoulder E8 of the drill.

The means 4| operates to hold the several slips 23 against actuation or inward movement until a core is received in the drill and passes upwardly between the slips. The means 40 includes a member having a part or arm 50 for engaging each slip 23 The slip controlling element or member is formed of a plurality of light rods or lengths of wire crossed and connected between their ends so as to form a plurality of radial arms 50. The lengths of rod or wire forming the'arms 50 may be welded or otherwise connected together. The member consisting of the plurality of radial arms 50 is in the nature of a spreader or spider engaging the slips 23. Releasable connections are provided between the arms 50 and the slips 23 Horizontal sockets or openings 5! are provided in the inner sides of the gripping slips 23 to receive the outer end portions of the arms 53. The openings 5| may be proportioned to more or less freely receive the end parts of the arms 50 so that the arms may be readily forced out of the openings when engaged by the core. The arms 50 may be bent or bowed downwardly and inwardly slightly as illustrated in Fig. 3 of the drawing.

It will be apparent how the slip controlling member may be assembled vbetween the slips 23"- by springing the arms 50 into the openings or sockets 5|. When the core drill is being run into the well, the arms 50 of the slip controlling member hold the slips 23* against inward movement and maintain them in positions against the upper portion of the shoulder 18 so that the core catcher is held against longitudinal movement in the drill. As the core catcher is held against movement, the slips 23 cannot be actuated or forced inwardly through the jars or shocks to which the drill may be subjected, while being lowered or run into the well. In this manner the gripping slips 23 are prevented from becoming wedged or set on the inclined shoulder 18. When the arms 50 or any one of the arms 50 is engaged by the upper end of the core during the drilling operation, the arms are sprung or bent upwardly so that their outer end portions pull out of the openings 5|. The slip controlling member is then held on the upper end of the core and enters the core barrel ll as the drilling continues. The core catcher is operated in the same manner as the core catcher illustrated in Fig. 1 of the drawing. When it is desired to remove the drill or break the core loose from the formation, the drill is raised and the inclined shoulder l8 cooperates with the slips 23 to force them into gripping engagement with the core.

The present invention provides a core catcher that is dependable in operation and that is not rendered imperative by the jarring action caused by assembling or making up the drilling string, as the drill is lowered into the well. The slip controllingmember positively holds the slips outwardly and thereby limits or prevents longitudi nal shifting of the core catcher in the drill. The means for controlling the slips or for preventing premature actuation of the slips is simple and inexpensive of manufacture and does not in any way interfere with the proper operation of the core catcher or drill. The slip controlling member may be easily and quickly assembled in the core catcher without modifying or altering the construction of any of the parts of the core catcher.

may appear to those skilled in the art or fall within the scope of the folowing claims.

Having described my invention, I claim:

1. A core catcher for use in a core drill including, a body adapted to be arranged in the drill, a plurality of core engaging members carried by the body operable inwardly into engagement with the core, and means for holding the members against inward movement releasable by the core, said means including an element engaging said members and releasably rigidly connected with the body.

2. A core catcher for use in a core drill including, a body adapted to be arranged in the drill, a core gripping slip carried by the body and operable inwardly to grip a core, and means for holding the slip against inward movement releasable by the core, said means including a member engaging the slip, and a frangible rigid connection between the member and the body, whereby the member is disengaged from the slip upon engaging a core during the drilling operation.

3. A core catcher for use in a tubular core drill having an inclined internal shoulder said core catcher including, a shiftable body in the drill, a plurality of circumferentially spaced gripping slips connected with the body and operatable inwardly to grip a core, a member within the series of slips operable to hold them against inward movement, and a shear pin rigidly connecting the member with the body.

JOHN H. HOWARD. 

